Introduction: Connector Magic

About: I have always been a geek and I see things differently than most people. I am healthy too and I love biology. Programming has always been my main interest. I have Basic Stamps, Arduinos and Picaxe in the form …

I have always been a geek. I tear everything apart to see what I can make of it. I just got into small robots with the starter pack and some BasicStamps and Arduinos. The Lets make robots kit is so complete you just stick it together with double stick foam tape and it starts running around. See the videos on the site. I needed an analogue cable for the infrared range finder that came in the kit.

I did not find any complete information on the analogue cable I needed. I found bits and pieces that lead me to the Arduino analogue and digital cables on They are not perfect, but they can be made to work if you know a little connector magic. The wires are not in the correct places and the JST connector is too big for the Sharp range finder’s connector.

Everything like printers, copiers and other small devices have connectors in them that you can make your own with connector magic. I am only going to show you common stuff like servo connectors and JST connectors that are used in a lot of stuff.

I used to have a connector tool. It looks like a small screwdriver except it is a hollow tube and the front half is open. This works by slipping between the wire and the connector blocks the locking tabs so you can get the connector out. has things like this. Anything thin like a pin can block the locking tabs too. It does not take too much to play with connectors and make your ideas come together.

I will start with the cable for a Sharp infrared range sensor that came in a robot kit from “” that was missing. does not ship the cable with the some of the sensors.

The sensor is JST Socket  1-Signal, 2-Ground, 3 +Volts ------the key slot faces out.
The Arduino Analogue JST 1-Signal(Blue), 2-Ground, 3 +Volts  -- to- 1-Signal, 2-Ground, 3 +Volts
The Arduino Digital JST 1-Signal(Green), 2 V2-Volts, 3 Ground  --   to- 1-Signal, 2 +V2-Volts, 3 Ground
A standard servo is the same as the digital cable. Connector 1- Signal, 2- V2-Volts, 3- Ground

Computer/Microprocessor boards are
Analogue 1- Ground, 2- Signal, 3- Volts
Digital 1-Signal, 2-V2-Volts, 3-Ground (Servo)
V2 volts is volts IN on most boards.
See the pictures

To correct the analogue cable pop out the Ground and Signal wires of the black connector and swap them to match your board. See your documents. Be very careful not to bend the locking Tabs too much or they will not lock any more. A little heat from a soldering gun tip or small heat gun fixes this. Just hold the locking tab down so the connector is held in place when you apply the heat. The locking tabs are very small, but made of fairly tough plastic.

I found that the JST connectors are made of tough fiber-ish plastic that does not work well with grinders or files. I used a Dremel sanding drum to get it to fit into the sensor connector. It was too tight.

Soldering wires onto connector you have to be careful to not get solder on the locking parts of the connector. I cut off the insulation crimps and then ground everything down until it fit into the connector sleeve. I only solder up to where the wire crimps are. I found it too hard to open the wire crimps. You can if you want to. Soldering on top of the crimped wires makes the connector too high to fit into the sleeve.

Look at the pictures and post comments.

Make connectors your own and build your dreams.